Blowhole (geology)

A Blowhole (German blowhole ) is a narrow opening at the end of a sea cave, which extends up through the cave ceiling outside in language use and in geology. If a surf wave impinges on the mouth of the cave, it is what, with a suitable geometry of the cavity and the right weather conditions through the cave walls, as performed in a funnel, for Blowhole to spectacular water fountains.

Known blowholes on different continents

• In Europe, the coasts of the British Isles are concerned. The Blowholes formed there in the limestone (geological called Gloup -. From Old Norse Gluppa ) found, for example in the Smoo Cave ( Highlands ) and on the coast of Orkney ( Gloup of Deerness, Gloup of stroma), Vat of Kirbuster Stronsay, as well as on the Shetland Islands ( Gloup of Yell ).
• The Kiama Blowhole at Kiama in New South Wales in Australia is probably the largest Blowhole in the world.
• Asia: In Oman you can on the beach of Salalah, about 20 km west of Salalah admire a number of blow holes. Depending on the tide and the waves can there admire sea water fountains that shoot out of the ground at the regular interval. The best time is during the Charifs.
• In New Zealand, blowholes found for example in the so-called Pancake Rocks.

Blowholes in inland caves

The term Blowhole is also used for a rare geological phenomenon, blown out in which, by the pressure difference between a closed system of caves and the surrounding air through a small hole on the surface or is sucked. Among the most famous blowholes this type are the Blowholes in Flagstaff, Arizona. Here it is estimated that a cave system is connected to a volume of at least 200 million cubic meters with the holes. Wind speeds can reach 13.4 m / s.